Rojectile



R. LUNDELL.

v PROJCTILE.

APPLICATION FILED JUNE I7. 1918.

Patented July 19, 1921 4 lNVENTOR 2M 4M BY 6 ATTORNEY UNIT 0 s'rrs ROBERT L'UnnEfn, or. YORK, N. Y.

EN'EQFEE PROJEGTILE' To all whom it may concern Be it knownthat ROBERT LUNDELL, a citizen of the United. States, and resident of New York city, in the county of New York and State of New York, has invented certain above it. In this manner, the effectiveness of the projectile is considerably increased as it isfcapable of striking a part of the target,

such as .a ship, which is below the water level and, therefore, not protected by armor and, consequently, extremely vulnerable. The

projectile is, moreover, especially adapted for use against submarines'or other craft which present little freeboard. To attain "the above mentioned object, the projectile has to be prevented from ricocheting upon a surface of water when fired at a low angle of elevation and the resistance offered by the air and the water to the-flight of the projectile must be kept within practicable limits.

Afurther object of the inventionis to pro-- vide a high velocity projectile which will permit the twist of the rifling of the gunbarrel'from which it is discharged to be reduced or kept within practical limits and this is effected by constructing the same in such manner that its speed of rotation will beincreased or affected-in a desirable manner during flight. Stillanother object is to provide a projectile with means for eflecting a proper spin thereof during flight in combination with means effecting stabilizing of the projectile when fired from a smooth bore 11. 1 It is well known that the ordinary shell will ricochet when striking a surface of water-at a comparatively small angle unless the shell is provided with a specially cupshaped or square nose, in which casethe resistance offered by the air or the water is materially increased which, of course, seriously interferes with .the efiective range of the shell. It is also well knownthat, in order to prevent a projectile from tumbling or keyholing,-it is necessary to impart thereto a considerable speed of rotation,to insure suflicient stability by reason of gyroscopic action. It is'also lmown that the speed. of rotationhasto be increased with an increase Specification of Letters Patent.

tion may be used.

Patented July 19, 1921.

Application filed June 17, 1918. Serial 1%. 240,423; I 1

in the length relative to the diameter-of the pro ectile, so that, withm'odern projectiles having a length of about 4.5 times the caliber, the twist of the rifling is equal to one complete turn fora barrel-,lengthj.of only about 25 calibers. ,Thetwis't of such rifling is considerable and the problem of prevent- 1ng stripping of the driving band or hands and rapid deterioration of the rifling in the gun-barrel presents serious difficulty.

For a clear understanding of my invention, reference ismade to the accompanying drawings, in which Figure 1 represents a of a projectile embodying my invention;

the line 2- 2 of Fig. 1;

longitudinal section Fig. 2 is across-sectionalview taken: on

' g- 3 showsin 'lol gltu dinal section the forward portion. of another form of my improved proj ectile whereof the constructlon. is v particularly conducive: to' increasing the speed of rotation of' the projectile after it has left the gun-barrel. V Fig.41 isa cross-sectional view taken on the line 44 of Fig. 3;

Fig. 5 shows in longitudinal section of another form of shell with which my inven- Referring tothe drawings, Figure 1 shows a shell or projectile substantially ordinary construction furnished witha driving band. 7

5 and arranged to receive the usual type of v base-fuse or. base-detonator which screws into the threaded portion ofthe shell at 6. The forward end of the. shell difiers slightly from the ordinary construction in that the shell has a threaded portion at 7 and a slight contraction at 8 of the filling chamber. 9 represents a steel tube or. attachment provided with a considerable number of spiral openings or slots lOuand between the said slots. accurately fitted over the pointed portion of the shell as clearly shown in the draw-v ing. The slots 10 are cut in the middle portion ofthe steel'tube andare sobeveled or shaped at the ends that. a; minimum resist? ance is offered to either air or water during the flight of .the projectile. Said slots are furthermore so proportioned in regard to their length, width and number; that the air orthe water' is provided with anexitarea through these slots" substantially equal to the entrance-area contained within the forward cylindrical portion of the steel tube.- Ilpon -;striking 'a sheet of water the connecting ribs 13 The-steel tube 9 is chisel-shaped forward edge of the steel tube will immediately bite or .cut into the water and the cylindrical portion of the tube will serve as a tubular rudder causingthe projectile to keep to itstrue trajectory until the speed of the same is very much reduced by the'resistance' of the water. It will be readily appreciated that, if there wereno outlets provided in the steel tube, the air or the water contained within the tube would be under great pressure on account of the high speed of the projectile and considerable resistance would beoffered to its travel.

I Even with adequate outlets there will still water within the tube but in the preferred be considerable pressure from theair or the form of my invention this pressure of the fiuid is utilized to affect the rotary motion of the projectile. The pitch of the slots shown in the drawing corresponds approximately to about one turn in twenty calibers.

Assuming that the shell is fired from a gun havin a moderate twist of rifiin' of one turn 1 steel casting is attached to the shell sub-' known soft steel cap used for'armor-pierc in thirty calibers theair or water pressing through the tube 9 and being forced outwardly by the pointed portion of the pro jectile, will exerta greater pressureupon the edges'll than upon the opposite edges of the ribs 13, thereby tending to 'caus'ethe projectile to gradually" increase its speed of rotation until it" approximates one turn in twenty calibers. The above description applies in a general way to the construction shown in Figs. 3 and 4. Instead of the 7 steel tube 9 and Fig.1 a machinedsteel casting or a die casting is used, which consists of a conical central portion 13 and nu- Inerous leaf-like ribs or blades 14 connecting said central portion to an outer tubular or cylindrical portion 15, as clearly shown in the drawings. It will be seen that the stantially like the steel tube in Fig. 1. It may, however, be attached in many different ways, in fact, the central conical portion 13 may be attached to the shell likethe well 'farmore powerful' rotary force thanthe ribs" 12 in Fig. 1 and'will quickly increase the speedof'rotation; of -the projectile after it has left the gun. It will be noticed that the greater portions of these blades are 7 spread out at the peripheryof the'casting,

so .that maXimum leverage or. torque for the rotary motion isobtained, The blades are also placed in a position (relative to the bodyof the projectilelwhere the air or water is underthe greatest compression; Attention may here be directed to the fact the projectile.

that various types of bombs and slow speed bullets or projectiles fired from smooth bore guns, .are' usually furnished with fan-sh aped tails .or propeller-blades in order to prevent tumbling or wabbling motion. Such devices are effective mainly because they serve to place the center of gravity of the bullet or the projectile, well forward. The rotary effort from a propeller-shaped tail-piece applied to a high speed projectile would, however, be insignificant because the device would travel in a rarefied atmosphere which would produce relatively little turning movement. Hence the importance of my' invention. is in placing the turning arrangement at the forward end of the projectile. As shown in Figs. 1 and 3' the tubular ribs 9' and 15 are relatively light in weight as compared-with the body portion of This is important in order that they offer little resistance and do not materially alter the ballistic characteristic of the projectile. Also the spiral blades or members are much longer in the axial direction of the projectile than in their radial direction in order to obtain imaximum torque. r

WVith certain ballistic proportions such as indicated in. Fig. 5 it is possible to further reduce the twist of the rifiing in'a gun-barrel. The projectile shown in Fig.5 has an exceptionally heavy head as shown at 16 and the base of the projectile is made exceptionally'light' by means of the tubular extension 17. This type. of projectile, having its center of gravity far forward, has less tendency to wabble after being fired than the ordinary-type and will quickly increase its stability in the air when furnished with the style of diving-cap shown in Fig. 3. Other means attached to the fuse-block 18 may in-certain cases be preferable to the tubular extension 17. By using a projectile of this type having a reduced length rela tive to its diameter, the rifling of the gun barrel may be entirely dispensed with and the projectile may advantageously be fired from a smooth 'boregun, the main point being to shift the centero-f gravity of the shell far enough forward toinsure sufficient initial stability until 'therequisite speed of rotation is attained by means of'the blades 15 or the like. I 'A diving-shell or a torpedo shell ofthe type described will naturally be very effective in a naval-engagement in that "it will readily reach the vulnerable portions of an armored ship below the waterline.

WVhen fired at a submarine which is just awash or with only the conning-tower or periscop'e showing the chances of scoring an effective hit will be considerable'increased.

I wish it .to be understood that I" do not limit my invention to the specificconstructions shown as various modifications in the design could be made and the invention emmembers and bodied in small arms projectiles and other widely differing forms without departing from the main features of the invention. Although Figs. 1 and 3 both show detachable diving-caps, such construction is not essential unless different qualities of metal are to be employed.

I claim:

1. A projectile having a reduced head and a diving-device to prevent ricocheting consisting of a tubular member surrounding and extending forward of said reduced head and being connected with the body portion of the projectile by a plurality of spiral members, between which open ports are formed for the escape of air or water which has entered the mouth of said tubular member during the flight of the projectile, said open ports having a combined cross-sectional area substantially equal to or greater than the area inclosed by the mouth of said tubular member.

2. A projectile having a reduced head and a diving-device to prevent ricocheting consisting of a tubular member surrounding said reduced head and a plurality of spiral members, between which open ports are formed, for connecting said tubular member to a base-member, the latter being secured in a detachable manner to the body portion of the projectile and said open ports having a combined cross-sectional area substantially equal to or greater than the area inclosed by the mouth of said tubular member. I

3. A projectile having a reduced head and means for engagement with the rifling of the gun-barrel from which the projectile is discharged to give an initial spin to the projectile, a tubular member surrounding said reduced head to prevent ricocheting and for receiving air or water under pressure during the flight of the projectile and helical members of greater twist than the rifling of the gun-barrel for utilizing the pressure of said air or water to increase the spin of the projectile after firing, open ports being formed between said helical said ports having a combined cross-sectional area substantially equal to or greater than the cross-section of the body portion of the projectile.

'ing relatively light projectile.

4. A projectile having a heavy and po' ted forward portion and a comparatively light rear portion, a tubular member extending 5. A projectile havlng an annular rimextending forward of the head end of the projectile and being spaced therefrom, said rim being of substantially the same diameter as the body portion of the projectile and beingconnected therewith by a plurality of in weight as compared spiral blades of substantially uniform twist v throughout their entire length, lateral ports being formed between said blades for the escape of air or mouth of said rim during the projectile.

6. A projectile having a pointed head porflight of the water which has entered the tion and a diving head comprising a tubular pointed portion of the projectile and of sub- 'metal rim spaced from and surrounding the 7 stantially the same diameter as the projec- I tile, and a plurality of blades connecting said rim with the projectile, and forming open ports between said bladesfor the escape of the air or water which has entered the mouth of said rim during the flight of the projectile.

7. A projectile having a-pointed head and a tubular member relatlvely light in weight 7 l as compared with the'body'portion of the -projectile, said tubular member extending over the pointed head and beingconnected with the body portion of the projectile by a plurality of spiral blades between which 1 exit areas are formed for the air or water confined by the tubular member, said exit areas being at least substantially equal. to the cross-section of the bodyportion of the Signed of New York and State of New York this 15th day of June, A. D, 1918.

at New York city, in the county ROBERT LUNDELL. 

